Low tension delivery for stuffer crimper



March. 4, 1969 B. s. HARRIS 3,430,311

LOW TENSION DELIVERY FOR STUFFER CRIMPER FIG. 1

Filed Nov. 2. 1966 5. FIG. 3

INVENTOR. BILLY STEVE HARRIS ATTORNEY United States Patent 2 Claims ABSTRACT OF THE DISCLOSURE A stufier crimper comprising an elongated tube forming a crimping and setting chamber. Feed rolls feed yarn for crimping into one end of said tube and advance the yarn as a core to a discharge point. A feeler wire extends into the tube at the discharge point to rest upon the end of the core and actuates a switch which controls the withdrawal motor. A choke wire extends into the tube in advance of the discharge end of the core to compact the core and exert controlled back pressure in the crimping zone. The core between the choke member and the feeler wire is confined by the tube but is under substantially no back pressure so that it is free to open up and become more pervious for cooling.

This invention relates to stutter crimpers and more particularly to a stuffer crimper having a delivery control mechanism by which the crimped yarn is withdrawn under a minimum tension and variation in tension.

An object is to provide a crimper of the above type wherein a predetermined back pressure is maintained on the core of crimped yarn in the crimping chamber while providing for the withdrawal of the yarn from the core under low tension conditions.

Another object is to provide a combination of pressure control means and core sensing means wherein the core is held under a minimum back pressure in the zone of the sensing means.

A further object is to provide a stuffer crimper having novel and improved means for maintaining the core of crimped yarn under a predetermined pressure in the crimping and setting zones while releasing the pressure at a point in advance of the point of extraction of the crimped yarn.

Various other objects and advantages will be apparent as the nature of the invention is more fully disclosed. The nature of the invention will be better understood from the following description, taken in connection with the accompanying drawing in which specific embodiments have been set forth for purposes of illustration.

in the drawing:

FIG. 1 is an elevation of a stutter crimper embodying the invention, with parts in section for clarity;

FIG. 2 is a transverse horizontal section taken on the line 22 of FIG. 1; and

FIG. 3 is a partial elevation of a stutter crimper utilizing a photoelectric cell for the core sensing device.

Referring to the drawing more in detail the invention is shown in FIGS. 1 and 2 as embodied in a stutter crimper comprising a heater block .10 mounted on suitable support members 11 and carrying a tube 12 forming a crimping and setting chamber and having heating elements 13 disposed in bores parallel to the tube 12 and adapted to supply heat to the portion of the tube within the block 10. A pair of feed rolls 14 and 15 are disposed below the end of the tube 12 in a position to feed a yarn 16 into the tube to be molded over and crimped against a mass of previously crimped yarn held as a core 17 in said tube. The lower end of the tube 12 is formed with a "ice saddle 18 extending over the bite of the feed rolls 14, '15 to form a confined crimping chamber.

The feed roll 14 is mounted on a shaft 19 journalled in a bearing in a support plate 20 and the feed roll 15 is mounted on shaft 21 journalled in a pivoted bracket 22 and is biased for pressure engagement with the yarn 16 as it is fed between the feed rolls into the tube 12. The shafts 19 and 21 are geared together for operation in unison by gears 23 and the shaft 19 is driven by suitable means such as a feed motor not shown.

A traverse guide shown as a roll 24 is mounted below the feed roll 14 and is provided with suitable means for traversing the yarn along the feed rolls 14 and 15 so as to minimize wear on the feed rolls and to improve the distribution of the yarn in the tube 12. The yarn 16 is fed from a cop not shown through a sewing machine tension device 27 to the traverse roll 24.

The tube 12 extends substantially above the top surface of the heater block 10 to provide a cooling zone wherein the crimped yarn is cooled somewhat before being withdrawn from the core within the tube. A choke device is disposed to engage the core 17 within the tube 12 at a point just above the top surface of the heater block 10 where the yarn is still at its highest temperature. The choke device is adapted to maintain the core of yarn in the crimping and heating zones at a substantially constant predetermined back pressure so as to maintain uniform crimping and setting conditions and ensure a uniform crimp.

The choke comprises a bracket 31 pivoted at 32 between arms 33 of a clamp 34 which is adjustably secured to the tube 12 just above the top of the heater block 10. The pivoted bracket 31 carries a wire 35 which extends through a slot 36 in the tube 12 to bear against the side of the core of yarn 17 in the tube at that point. The wire 35 is formed with a smooth loop portion 37 which provides a smooth surface in contact with the yarn and also extends downwardly beyond the pivoted bracket 31 to carry an arm 38 on which a weight 39 is threaded for adjustment along the arm so that the pressure exerted by the wire 35 on the core 17 can be varied depending on the back pressure desired.

The arrangement is such that the wire 35 compresses the core -17 against the opposite side of the tube 12 and thus forms a choke to retard the advance of the core, thus exerting a controlled back pressure on the core of yarn in the entire area between the point of contact of the wire and the bite of the feed rolls.

A sensing device is disposed on the tube 12 at a point beyond the choke. This device is shown in FIGS. 1 and 2 as comprising a feeler wire 41 extending through a slot 42 in the tube 12 to rest on the top surface of the core 17 at the level of its discharge point. This feeler wire 41 is pivoted at 43 to a microswitch 44 and engages a pin 45 which is adapted to open and close the switch. The switch 44 is mounted on a bracket 6 which is clamped to the tube 12 by a clamp 47 and is adjustable along the tube. The microswitch 44 is connected to control the operation of the feed roll motor or of the winder motor so as to vary the input or the output of the tube in a sense to maintain the discharge point at a substantially constant level. The feeler wire 41 rests lightly on the core so as not to exert appreciable pressure thereon. Hence the portion of the core between the choke wire 35 and the feeler wire 41 is substantially unconfined. Hence the core in this zone tends to open up and become more permeable to air so as to facilitate the initiation of the cooling step. Although a microswitch is shown it may be desirable to use a more sensitive control switch such as for example a mercury switch.

The crimped yarn is withdrawn from the top of the core through a ceramic eye 48 and a tension gate 49 to a constant speed winder 50 including a winding 51 and a driving roll 52 which is driven at constant speed by a motor not shown and on which the winding 51 rests and is driven at a constant peripheral speed. The tension gate 49 is mounted by a bracket 53 on the tube 12 at a point above the bracket 46.

Since the yarn is lightly packed in the area above the choke device and the feeler wire 41 rests lightly on the top of the core the yarn is pulled from under the feeler wire under a minimum tension so that the crimp is not appreciably reduced. This is to be distinguished from the action of a weight or plug resting on the top of the core which would exert substantial pressure on the yarn which is pulled out from under the same and would tend to iron out the crimp as the yarn is withdrawn. Hence the yarn produced by the apparatus of the present invention has improved crimp retentivity and uniformity. By the time the yarn is wound on the package it has cooled below its setting temperature so that the crimp remain set in the yarn and is restored by the usual rebulking technique as by heating to a temperature somewhat below its original setting temperature.

Apparatus of this type is particularly adapted for use in crimping yarns which are sensitive to variations in crimping conditions and are difficult to crimp uniformly,

such for example as polyester fibers.

The embodiment of FIG. 3 is similar to that of FIGS. 1 and 2 except that the feeler wire 41 of FIG. 1 is replaced by a photoelectric cell sensing device. The parts which are identical with those of FIG. 1 have been given the same reference numbers with the suffix a and will not be redescribed. It is to be understood that the crimping tube, heater block, feed rolls and choke device may be the same as in FIG. 1. Only the portion of the apparatus above the heater block has been shown in FIG. 3. In this position the choke wire 35a and mounting are the same as above described. In the sensing zone a photoelectric cell 60 is mounted on a plate 61 adjustably secured on the tube 12a by a clamp 62. A light source 63 is mounted on the bracket 61 in a position to project light rays through slots 64 in the tube 12a onto the photoelectric cell 60. These light rays are interrupted when they are intercepted by the top of the core 17a. The light source 63 is adjustable vertically on the bracket 61 by a threaded screw 65.

The arrangement of FIG. 3 is such that the photoelectric cell -60 actuates either the feed roll motor or the winder motor in a sense to maintain the top or the core 17a at a substantially constant level. This embodiment eliminates even the light pressure exerted by the feeler Wire 41 of FIGS. 1 and 2 and still further reduces the tension on the yarn as it is withdrawn from the top of the core and fed to the winder. Since the weight of the amount of yarn between the choke and the sensing means is negligible the back pressure in the crimping and setting zones remains constant as the level of the top of the core is raised and lowered slightly in the operation of the sensing device.

What is claimed is:

1. Apparatus for crimping yarn comprising a tube forming a crimping and setting chamber, feed rolls disposed to feed yarn for crimping into the lower end of said chamber under a pressure to cause a core of crimped yarn in said chamber to advance upwardly along said tube to a discharge point in a continuous column, a feeler member extending through said tube at said discharge point to rest upon the end of said core, means withdrawing the crirnped yarn from said discharge end of said core, means responsive to the movement of said feeler member to control the relative rates of feed and withdrawal of said yarn so as to maintain said discharge end at a selected point, and a choke member comprising a pivoted wire disposed to extend through a slot in said tube at a point in advance of said discharge end and having a smooth loop portion engaging said core, and means biasing said choke member to exert transverse pressure on said core for impeding but not interrupting the advance thereof whereby the back pressure on said core is maintained due to said choke member and the portion of said core between said choke member and said feeler member is held under substantially no back pressure while being confined by said tube as a continuous core.

2. Apparatus as set forth in claim 1 in which a heating member is disposed to supply heat to a portion of the length of said chamber for heating the crimped yarn therein to a setting temperature, said tubular member extends beyond said heating member to form an enclosed cooling and discharge zone and said choke member is disposed at a point beyond said heating member.

References Cited UNITED STATES PATENTS 3,000,059 9/ 1961 Russo et al 28-72 3,200,466 8/1965 Duga et a1. 28-72 3,248,770 5/1966 Shattuck et a1 2872 X 3,253,314 5/1966 Shattuck 281 3,345,719 10/ 1967 Schatz et al 281 MERVIN STEIN, Primary Examiner. 

